Method for updating and restoring operating software in an active region of a network element

ABSTRACT

A method for replacing a current operating software with a new operating software in a working network environment during network operations while also preserving a backup for the replaced operating software. The method including active or non-active memories based on the operating software stored therein. The active and non-active memories being interchangeable to accommodate the new operating software without stopping operation of the network or active memory.

FIELD OF THE INVENTION

The present invention relates generally to replacing or updating ofoperating software in an active region of a network element while thenetwork element is active, running updated software as well as restoringthe operating software such as in case of update malfunction.

BACKGROUND

As computer networks grow and expand it is important that all elementsof the network operate in a coordinated fashion. One of the importantsteps in this process is to ensure that software on the various networkelements is operated and updated in a coordinated manner. The problem ofupdating pre-existing, region-dependent software without affecting theregion-dependent nature of the software and transporting the updatedsoftware to the destination (e.g., via the internet), extracting,loading and merging the updated software has been recognized, forexample, by Randall in U.S. Pat. No. 5,978,916. This patent teaches amethod, system and computer program for updating software with a commonupdate module.

Certain networks require more than a coordinated software update. Forexample, communications networks have to operate with minimal downtimefor administration and maintenance. When system files or operatingsoftware is being updated, the network element has to maintain fullcapability of transporting communication traffic and ensure minimuminterruption in administration and maintenance capability. This is adifficult task, since operating software consists of files that arewrite-protected or access-locked to avoid accidental overwriting duringroutine operation.

In U.S. Pat. Nos. 6,199,203; 6,154,878 and 6,202,205 Saboff et al. teachmemory management techniques for on-line replaceable software, e.g., asoftware library, such that the state of the software component ispreserved after an update to the software component. This isaccomplished by allocating two types of memory: transient memory andenduring memory (to be preserved between two calls of the library). Inthis method, when new version of the software is updated software fromthe transient memory is released, while the enduring memory is preservedfor use by new software versions. In U.S. Pat. No. 5,764,989 Gustafssonet al. teach an interactive program or software development system whichobviates the need to halt execution of a program under development orduring a maintenance update to correct programming errors.Unfortunately, Saboff's technique is limited to the patching of memoryand it cannot be applied to upgrade operating software in acommunications network and Gustafsson's teaching cannot be extended toupdates of operating systems with the above-mentioned interruptionrequirements in communications networks.

In fact, updating of system software in a network challenges themanagement of operating systems as well as operational continuity,memory management and data recovery. In U.S. Pat. No. 5,715,462 Iwamotoet al. present an updating and restoration method of system file that isdesigned for operating system (OS) updates and takes advantage ofstoring the same OS in separate memory areas. The executing OS in thefirst memory area is terminated and the OS in the second area isinitiated. After the system files stored in the first area are releasedfrom access lock, substitute files provided in advance by using a filereplacing function of the second OS replace them. When such as filereplacement fails for some reason, the original operating system filesare immediately restored.

Iwamoto's teaching moves a long way to solving the problem of upgradingor updating of operating system software and can be applied incommunication networks. It offers safety in that it preserves files toprovide for recovery and reinitiating of old operating software in caseof failure. Unfortunately, Iwamoto's approach has several drawbacks.First, there is a lengthy period of loss of visibility to a networkmanager. This is the time involved in performing two terminations andactivations or two reboot operations and new software installation. In asuccess scenario this time can be about 15 minutes, and close to onehour in a worst-case failure scenario. Second, this update method haspoor failure handling capability with respect to detecting the conditionof the system and reporting alarms. Since the application softwarecannot be started during the procedure, it is not possible to use thealarm mechanisms provided by the application software. Third,implementation and testing are complicated in this approach. Thecombinations of failure cases during the reboots can be dramatic andcause enormous increases in implementation and testing time.

Therefore, the problem of rapid, simple and effective operating systemupdates in networks with minimal loss of visibility to a network managerremains unsolved. This problem is especially acute in communicationsnetworks that have to maintain high visibility and error-free operation.

OBJECTS AND ADVANTAGES

In view of the above, it is an object of the present invention toprovide a method for updating or replacing a current operating softwareand current files with new operating software and new files in anefficient, simple and rapid manner. Specifically, it is envisioned thatthe method provide for replacing the operating software and files withminimum loss of visibility to the network manager.

It is another object of the invention to ensure that the method forupdating the system software sustains minimal loss of visibility even incase of worst-case failure scenarios.

It is yet another object of the invention to ensure that theimplementation of the update method reduces failure cases during rebootsby minimizing the number of reboots that need to be performed.

These and other objects and advantages will become apparent upon readingthe detailed description.

SUMMARY OF THE INVENTION

The objects and advantages of the invention are achieved by a method forreplacing a current operating software working with current files by anew operating software working with new files. Prior to replacement, thecurrent operating software and current files reside in an active regionof a network element, while the network element is active and maintainsa prior operating software in a non-active region. In accordance withthe method, the prior operating software is preserved in the non-activeregion and new operating software is downloaded to the non-activeregion. The new operating software is installed in the non-active regionand the current files are saved. The current files are updated to createupdated files conforming to the new operating software. The networkelement is then rebooted such that the active region and the non-activeregion are swapped, thereby replacing the current operating softwareworking with the current files with the new operating software workingwith the updated files.

The method further includes the step of reinstalling in the non-activeregion the prior operating software that was preserved in the non-activeregion. A redistribution of the current files to the active region andprior files to the non-active region is also performed.

In a preferred embodiment the network element has a processing elementmodule (PEM) and a persistent storage module (PSM) and the active regionis partitioned or distributed between the PEM and PSM. The non-activeregion is also partitioned or distributed between the PEM and PSM. Inthis embodiment, the current files are saved in the active region of thePSM and in the active region of the PEM. Furthermore, when downloadingthe new operating software it is convenient to download load files ofthe new operating software into the non-active region of the PSM andPEM.

The prior operating software has prior files, which typically include adatabase. The step of preserving the prior operating software includesstoring the load files of the prior operating software in the non-activeregion in the PSM. The prior files are also preserved in the non-activeregion in the PEM. The prior operating software is erased duringinstallation of the new OS files.

Because of space, it is also preferable to download the new operatingsoftware by downloading load files of the new operating software intothe non-active regions defined in the PSM. Installation of the newoperating software is then accomplished through extracting andinstalling the load files to build the new operating software. The newoperating software is installed in the non-active region of the PSM andPEM.

In one embodiment, the current files are stored in the active region.For example, the current files can be stored in the active region of thePSM and PEM. Thus, after the reboot, these files will be located in thenon-active region of the PSM and PEM. These current files typicallyinclude a database.

The method of the invention can be used to upgrade or update operatingsystems in network elements belonging, e.g., to a communication network.In one embodiment, the new operating software is a software release ofthe current operating software. Of course, the new operating softwarecan also be a maintenance version or any other modified version of thecurrent operating software.

When the new operating system malfunctions or if the networkadministrator wishes to revert to the current operating software for anyreason, the current operating software can be restored. The step ofrestoring involves rebooting the network element such that the activeregion and non-active region are swapped again, provided the swap rebootwas successful. This replaces the new operating software working withupdated files by the current operating software working with the currentfiles.

The invention also includes a storage medium that performs theabove-enumerated steps of replacing the current operating softwareworking with current files by the new operating software working withupdated files. Specifics and details about the method of invention andthe steps stored in the storage medium are found in the followingdetailed description with reference to the attached drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a communication network in which themethod of the invention is applied.

FIGS. 2A–I are diagrams illustrating the steps of the method.

DETAILED DESCRIPTION

The method of invention will be best understood by first examining acommunication network 10 of FIG. 1, in which the method is applied. Itwill be clear to a person skilled in the art that communication network10 is an exemplary network, e.g., the internet, and that other networksand computer systems exhibiting different network architectures can takeadvantage of the method.

Communication network 10 has a host computer 12 and a file server 14.Host computer 12 is, for example, a data base machine that supervisesthe operation of network 10. Thus, host computer 12 oversees thetransmission and reception of data 20 within network 10. Host computer12 also manages file server 14 to which files can be stored and fromwhich files, such as files 16, may be sent to any given network element,such as network element 18, belonging to network 10.

Network 10 has various resources including data transmission lines(e.g., optical fibers), repeater stations, routers, filters and thelike. These resources transmit and distribute data 20 throughout network10 and are generally indicated by reference 22. A person skilled in theart will appreciate that any specific type of network will beprovisioned with appropriate resources 22.

Network element 18 is connected to network 10 such that it can send andreceive data 20. Network element 18 includes a number of circuits, dataprocessing devices and modules 24. The modules include a processingelement module (PEM) 26 and a persistent storage module (PSM) 28. PEM 26has a central processing unit 30, a first storage unit 32 and a secondstorage unit 38. In this embodiment both storage units 32, 38 are harddisk drives, but a person skilled in the art will recognize that anyother suitable storage units affording sufficiently rapid access timesfor processing functions which PEM 26 is to perform in managing thecommunications of network element 18 can be employed. PSM 28 is equippedwith its own central processing unit 34 and its own storage units 36, 40which are also hard disk drives in this embodiment. PSM 28 is designedto provide redundant storage to PEM 26, in case of failure.

Hard drive 32 is selected as the active drive of PEM 26 and hard drive38 as the non-active drive. In PSM 28 hard drive 36 is chosen as theactive drive and hard drive 40 as the non-active drive. An active region42 is defined on drives 32, 36 in PEM 26 and PSM 28. A non-active region44 is defined on drives 38, 40 in PEM 26 and PSM 28. Active and passiveregions 42, 44 are thus partitioned or distributed among hard drives 32,36 and 38, 40 and the division between passive and active regions 42, 44is indicated by a dashed line. The software and files in active region42 are access-locked or write-protected to prevent accidentaloverwriting during routine operation of network element 18.

An external network manager 46 has access to network element 18 viainterface 48. External network manager 46 monitors the operation ofnetwork element 18 and requires that the operations being performed bynetwork element 18 be visible. Network manager 46 requires maximumvisibility, preferably at all times, of the operation being performed bynetwork element 18 to ensure that administrative and maintenancefunctions can be performed.

Active region 42 in PEM 26 and PSM 28 is synchronized by appropriatelycontrolling drives 32, 36 as indicated by arrows S. Such synchronizationis well understood by those skilled in the art. Meanwhile, non-activeregion 44 in PEM 26 and PSM 28 is not synchronized. Non-active region 44in PEM 26 and PSM 28 is not write-protected and serves to store files.In fact, active region 42 in PEM 26 stores a current operating software(OS) 50 and current files 52. OS 50 works with current files 52, whichtypically include a database, to coordinate the operation of networkelement 18. A copy of current OS 50′ and of current files 52′ is alsoinstalled and maintained in synch in active region 42 of PSM 28.Non-active region 44 on both PEM 26 and PSM 28 contains a prior OS 54,54′ and prior files 56, 56′ respectively. Additional files can also bestored in non-active region 44, especially in PSM 28. For that reason,it is preferable that the capacity of hard drive 40 be large enough toaccommodate numerous software files over and above prior OS 54′ andprior files 56′.

Modules 24 also include transport cards, of which only two cards 72, 74are shown for simplicity. Transport cards 72, 74 are typically circuitpacks placed on the shelves of network element 18 alongside PEM 26 andPSM 28, but in different slots. Cards 72, 74 perform all data trafficprocessing functions, including amplifying, multiplexing/demultiplexing,wavelength conversion and other functions required to process and routedata 20. To perform these functions, transport cards 72, 74 runcorresponding applications. Thus, when active, transport cards 72, 74carry a software load including an application, a boot loader, amicroboot loader and any other necessary software (e.g.,field-programmable gate array (FPGA) assignments), as is known to thoseskilled in the art. Preferably, the software on transport cards 72, 74is stored in an active flash memory region 76 and a non-active flashmemory region 78 on each transport card 72, 74. Both the active andnon-active regions carry the exact same software loads for redundancy.

During normal operation current OS 50 in conjunction with current files52 operates network element 18 and uses non-active region 44 on drives38, 40 for backing up and storing files. Synchronized current OS 50′ andcurrent files 52′ also in active region 42 can be used to recover PEM 26after a failure, e.g., in case of drive 32 malfunction. It should benoted that in a typical network element 18, PSM 28 cannot use current OS50′ and current files 52′ to operate network element 18 in case offailure of PEM 26.

If it is desired that network element 18 operate with prior OS 54, areboot procedure is performed. During reboot OS 54, 54′ with files 56,56′ are re-activated by swapping active region 42 and passive region 44.Rebooting drives 32, 36, 38, and 40 in accordance with standardprocedures is known in the art. The actual flow of data 20 is processedand routed by transport cards 72, 74 under the direction of softwareexecuting from active region 76 of their flash memories. In case offailure or malfunction of transport cards 72, 74 the software innon-active flash memory region 78 is activated and used to direct thetraffic of data 20.

Periodically, a new release, maintenance update or otherwise new,patched, modified or upgraded OS is to be installed on network element18. Such new OS can be distributed from file server 14 on instructionsfrom host computer 12 and delivered in the form of load files 16 tonetwork element 18. Alternatively, the new OS can be provided throughnetwork administrator 46 or by otherwise loading new OS via a localinterface from an external device, e.g., an external removable diskdrive.

It is important that the replacement of current OS 50, 50′ working withcurrent files 52, 52′ by new OS working with new files be performed in amanner which minimizes loss of visibility to network manager 46,minimizes probability of malfunctions and uses the least rebootoperations possible. The present method provides for such replacement,as will now be explained in reference to FIGS. 2A–I.

FIG. 2A illustrates the condition of active region 42 and non-activeregion 44 on PEM 26 and PSM 28 prior to any updating activity. Duringthis time, network manager 46 is able to monitor and maintain theoperation of network element 18. Current OS 50, in the presentembodiment OS version X.1.0, and current files 52 installed in activeregion 42 of PEM 26 are controlling the operation of network element 18.Since OS X.1.0 50 and current files 52 on PEM 26 are synchronized withOS X.1.0 50′ and current files 52′ on PSM 28, OS X.1.0 50′ and currentfiles 52′ can be used to recover PEM 26 in case of a malfunction.

Non-active region 44 on both PEM 26 and PSM 28 contains prior OS 54,54′, in this case X.0 and prior files 56, 56′ respectively. Thus, it isalso possible to reboot PEM 26 and PSM 28 such that prior OS 54, 54′ andprior files 56, 56′ are in active region 42 and current OS 50, 50′ alongwith current files 52, 52′ are in non-active region 44. This process canbe used to revert to prior OS 54, 54′ for any desired reason. Theprocess involves rebooting PEM 26 and PSM 28 and placing drives 38 and40 in active region 42 while assigning drives 32, 36 to non-activeregion 44 (see FIG. 1).

The state illustrated by FIG. 2A with current OS X.1.0 50, 50′ and priorOS X.0 54, 54′ stored in active and non-active regions 42, 44 of PEM 26and PSM 28 is frequently referred to as the activated state. Therebooting procedure is also referred to as a swap reboot and is familiarto those skilled in the art.

FIG. 2B illustrates the first step taken in replacing current OS X.1.050, 50′ working with current files 52, 52′ by new OS and new files whennetwork element 18 is in the activated state shown in FIG. 2A.Specifically, before the replacement, prior OS X.0 54, 54′ and priorfiles 56, 56′ are preserved in non-active region 44. Preferably, thepreservation involves saving load files 62 of prior OS X.0 54 and ofprior files 56 where sufficient storage space is available.Conveniently, this space is provided in non-active region 44 of PSM 28.Prior OS X.0 54 will be erased after load files 62 of prior OS X.0 54are stored and during installation of new OS files. Alternatively, ifdrives 38, 40 have sufficient storage capacity, prior OS X.0 54, 54′ andprior files 56, 56′ can be retained in non-active region 44 of PEM 26and PSM 28.

FIG. 2C illustrates the next step, during which load files 64 of new OSX.1.1 66 are downloaded to non-active region 44 of PEM 26 and PSM 28.Alternatively, load files 64 can be downloaded only to non-active region44 of PSM 28 and from there be installed in non-active region 44 of PEM26. This approach is preferable, as it conserves disk space.

Load files 64 can be delivered through network 22, i.e., they can beembedded in files 16 sent from file server 14 upon authorization of hostcomputer 12. Alternatively, load files 64 can be supplied locally. Forexample, network element 18 may be equipped with a drive for readingremovable media such as a CD drive (not shown) and load files 64 can beprovided on a readable storage medium such as a CD. In still anotherapproach, a personal computer (PC) can be connected to network element18 via a craft interface port to download load files 64. A personskilled in the art will recognize that there are numerous ways in whichload files 64 can be delivered to network element 18.

New OS X.1.1 66 is installed in non-active region 44 of PEM 26. Inaddition, a redundant copy of new OS X.1.1 66′ is installed innon-active region 44 of PSM 28. The installation involves extractingload files 64 installing the extracted files and building new OS X.1.166 and new files 68 on PEM 26 and respective copies of OS X.1.1 and ofnew files 66′, 68′ on PSM 28. During this process prior OS X.0 54, 54′and prior files 56, 56′ are overwritten. In other words, prior OS X.054, 54′ as well as prior files 56, 56′ are erased when new OS X.1.1 66,66′ and new files 68, 68′ are installed. It should be noted thatthroughout this process the operation of network element 18 is visibleto network manager 46.

In the next step shown in FIG. 2D new files 68, 68′ are updated with theinformation being used by current files 52, 52′. Current files 52, 52′typically contain a database and other files that are formatted tocooperate with current OS X.1.0 50, 50′. It is important that thecontents of this database and of the other files be transmitted to newfiles 68, 68′ so that new OS X.1.1 66 can pick up the work seamlesslyfrom current OS X.1.0 50. This can be done in any suitable manner knownto those skilled in the art. For example, the data from the database andany other files belonging to current files 52, 52′ can be imported intonew files 68, 68′ directly. Alternatively, the database and files can beconverted or reformatted to conform to the standards of files 68, 68′and merged. In any case, this step should be performed just prior to thesubsequent steps to ensure that new OS 66, 66′ can start operating withnew files 68, 68′ containing up-to-date information.

In the subsequent step, illustrated in FIG. 2E copies of current files52, 52′ are saved as backup files 70, 70′ on PEM 26 and PSM 28respectively. Backup files 70, 70′ are kept in active region 42 of PEM26 and PSM 28. It should be noted that up until the step of FIG. 2E,network manager 46 can monitor the activity of PEM 26 and PSM 28.

During the next step, network element 18 is rebooted. This procedure isillustrated in FIG. 2F and it involves restarting both PEM 26 and PSM 28and re-assigning drives 32, 36, 38, and 40. During the restartingprocedure active and non-active regions 42, 44 are redistributed orrepartitioned. In particular, drives 32, 36 are designated as non-activewhile drives 38, 40 are selected as active. Thus, the rebootingoperation swaps the active and non-active regions 42, 44. Formerlynon-active region 44 of PEM 26 and PSM 28 is now active region 42′ whileformerly active region 42 of PEM 26 and PSM 28 becomes non-active region44′. The appropriate rebooting procedures are well known to thoseskilled in the art.

As a result of the reboot, current OS X.1.0 50, 50′ working with currentfiles 52, 52′ are in non-active region 44′. Meanwhile, new OS X.1.1 66,66′ working with new files 68, 68′ are in active region 42′. Thus, thereboot replaces current OS X.1.0 with new OS X.1.1 in active region 42′.Meanwhile, backup files 70, 70′ of current files 52, 52′ are innon-active region 44 of PEM 26 and PSM 28 respectively. During therebooting operation network element 18 is not visible to network manager46.

After the reboot new OS X.1.1 66, 66′ and new files 68, 68′ are placedinto operation and synchronized, as shown in FIG. 2G. At this timenetwork element 18 starts running under the direction of new OS X.1.1and communication with network element 18 is re-established. At thispoint, active region 42′ is fully functional and network manager 46 canonce again monitor the activity of network element 18. In other words,visibility of network element 18 is restored at this time.

To complete the process backup files 70, 70′ and load files 62 stored inactive and non-active regions 42′, 44′ are redistributed. In particular,backup files 70, 70′ are moved to active region 42′ on PEM 26 and PSM 28respectively. Additionally, load files 62 of prior OS X.0 54, 54′ andprior files 56, 56′ are moved to non-active region 44′ on PSM 28.

FIG. 2H illustrates a clean-up step performed after successfulinstallation of new OS X.1.1 66, 66′ and new files 68, 68′. The clean upinvolves removing current OS X.1.0 50, 50′ and current files 52, 52′from non-active region 44′. This is done by overwriting prior OS X.0 54,54′ and prior files 56, 56′ in non-active region 44′ on PEM 26 and PSM28 respectively. This is done in cases where network manager 46 wishesthat upon reboot prior OS X.0 54, 54′ rather than current OS X.1.0 50,50′ operate network element 18. Such reboot can be performed if desiredby the network manager 46 or for any other reason. Before the reboot,prior files 56, and the database of prior files 56 in particular, can beupdated with the data from new files 68 if possible.

If sufficient space is available, current OS X.1.0 50, 50′ or its loadfiles can be stored for eventual future use. Also, back-up files 70 ofcurrent files 52, 52′ containing the database can be stored to asuitable storage device (not shown) in network element 18.

FIG. 2I illustrates the result of the process. Network element 18 isonce again in the activated state and is committed to operating with newOS X.1.1 66, 66′ and new files 68, 68′.

It should be noted that new OS X.1.1 66, 66′ and new files 68, 68′ canbe aborted upon instructions from network element 18. In this case,prior software 54, 54′ and prior files 56, 56′ are re-activated byanother reboot and swap of the active and non-active regions 42′, 44′ torevert to the previous configuration.

The method of the invention can be used to upgrade or update OS softwareand files in network elements belonging to a communication network andoperating on live data or in other networks. The method limits the lossof visibility of network element 18 because only one reboot is necessaryto switch network element 18 to the new OS, after which network element18 continues working seamlessly with actual data. During other stages ofthe OS replacement, even in case of most of the failure recoveryscenarios, network manager 46 has visibility of the operations beingexecuted on network element 18.

Implementation and testing is straightforward because the failure pathin failed upgrades is conceptually, the exact reverse of the successpath. Furthermore, failures in any recovery activities performed in thenon-active region will not cause the entire method to fail. This isbecause OS in the current region is already updated successfully andrunning when the final operations in the non-active regions are beingperformed. In fact, the problems in the non-active region can besupplied with appropriate alarms and fixed during separate steps. Suchalarms and steps are well known to those skilled in the art.

The method of invention can be used in any networks. It fact, it isadvantageous to also use this method for updating a current card OS witha new card OS in transport cards 72, 74 of network element 18.Preferably, at this time, new OS X.1.1 66, 66′ and new files 68, 68′ arealready downloaded and installed in non-active region 44 of PEM 26 andPSM 28.

The process of updating transport cards 72, 74 is performed by followingthe steps shown in FIGS. 2A–E and operating on active and non-activeflash memory regions 76, 78. Thus new card OS and accompanying new cardfiles which are to replace current card OS and current card files areloaded. After PEM 26 and PSM 28 are successfully rebooted and active andnon-active regions 42, 44 are swapped to active and non-active regions42′, 44′ the update of transport cards 72, 74 is resumed by followingthe steps illustrated in FIGS. 2F–I. During these steps, non-activeflash memory region 78 becomes the active flash memory region and iscommitted with new card OS and new card files. Failure in delivering newOS or files, or failure in completing restart during the reboot and swapof active and non-active flash memory regions 76, 78 is considered asfailure of the entire process. In other words, the upgrade of networkelement 18 is considered a failure and reboot to revert back to currentOS and current files is performed on PEM 26, PSM 28 as well as ontransport cards 72, 74.

The method of invention can be used in many types of networks and atvarious levels. As illustrated in the above embodiment, the method caneven be performed to update various components of the same network. Inanother embodiment, the steps of the method are stored in a storagemedium. The method can thus be loaded into any suitable processor on anetwork requiring OS replacement and executed. A person skilled in theart will recognize that many extensions and alternative embodiments ofthe invention are possible and that the full breadth of the invention ishence defined by the scope of the appended claims and their legalequivalents.

1. A method for replacing a current operating software working withcurrent files in a network element comprising a processing elementmodule and a persistent storage module, each having an active region anda non-active region, said current operating software and said currentfiles residing in said active region of said processing element moduleand said persistent storage module while said processing element moduleand said persistent storage module are active and wherein saidnon-active region of said processing element module and said non-activeregion of said persistent storage module maintain a prior operatingsoftware, said method comprising: preserving said prior operatingsoftware in said non-active region of said processing element module andin said non-active region of said persistent storage module; downloadinga new operating software to said non-active region of said persistentstorage module; installing said new operating software in saidnon-active region of said processing element module and in saidnon-active region of said persistent storage module; saving said currentfiles; updating said current files to create updated files conformingwith said new operating software; and rebooting said network elementsuch that said active region and said non-active region of saidprocessing element module are swapped, and said active region and saidnon-active region of said persistent storage module are swapped, therebyreplacing said current operating software working with said currentfiles with said new operating software working with said updated files;wherein said network element concurrently utilizes the current operatingsoftware and current files residing in said active region of saidprocessing element module during said downloading to said non-activeregion of said persistent storage module and installing of said newoperating software in said non-active region of said processing elementmodule and in said non-active region of said persistent storage module;wherein the processing element module comprises a first centralprocessing unit, a first physical storage unit for the active region,and a second physical storage unit for the non-active region, and thepersistent storage module comprises a second central processing unit, athird physical storage unit for the active region, and a fourth physicalstorage unit for the non-active region; and wherein the active region ofthe processing element module and the active region of the persistentstorage module are synchronized and access-locked, and the non-activeregion of the processing element module and the non-active region of thepersistent storage module are not synchronized and not access-locked. 2.The method of claim 1, further comprising reinstalling in saidnon-active region of said processing element module and in saidnon-active region of said persistent storage module after rebooting saidprior operating software preserved in said non-active region.
 3. Themethod of claim 1, further comprising redistributing said current filesto said active region of said processing element module and in saidactive region of said persistent storage module and said prior files tosaid non-active region of said processing element module and in saidnon-active region of said persistent storage module.
 4. The method ofclaim 1, wherein said step of saving comprises saving said current filesin said active region of said persistent storage module.
 5. The methodof claim 4, wherein said step of saving further comprises saving saidcurrent files in said active region of said processing element module.6. The method of claim 1, wherein said step of downloading comprisesdownloading load files of said new operating software into saidnon-active region of said processing element module.
 7. The method ofclaim 1, wherein prior operating software has prior files and said stepof preserving said prior operating software comprises storing load filesof said prior operating software in said non-active region of saidpersistent storage module.
 8. The method of claim 7, further comprisingpreserving said prior files in said non-active region of said persistentstorage module.
 9. The method of claim 7, further comprising erasingsaid prior operating software.
 10. The method of claim 1, wherein saidstep of downloading said new operating software comprises downloadingload files of said new operating software into said non-active region ofsaid persistent storage module.
 11. The method of claim 1, wherein saidstep of installing said new operating software comprises installing saidnew operating software in said non-active region of said persistentstorage module and in said non-active region of said processing elementmodule.
 12. The method of claim 1, wherein said step of saving saidcurrent files comprises saving said current files in said active regionof said persistent storage module and in said non-active region of saidprocessing element module.
 13. The method of claim 1, wherein saidcurrent files comprise a database.
 14. The method of claim 1, whereinsaid step of downloading comprises downloading load files of said newoperating software and extracting said load files to build said newoperating software.
 15. The method of claim 1, wherein said newoperating software comprises a software release of said currentoperating software.
 16. The method of claim 1, wherein preserving saidprior operating software comprises storing load files of said prioroperating software.
 17. The method of claim 1, further comprisingrestoring said current operating software.
 18. The method of claim 17,wherein said step of restoring comprises rebooting said network elementsuch that said active region and said non-active region of saidprocessing element module are swapped, and said active region and saidnon-active region of said persistent storage module are swapped, therebyreplacing said new operating software working with said updated fileswith said current software working with said current files.
 19. Themethod of claim 17, wherein said step of restoring is performed upon amalfunction.
 20. The method of claim 1, wherein said network elementfurther comprises transport cards having an active flash memory regionand a non-active flash memory region, and a swap reboot is performed insaid active flash memory region and said non-active flash memory regionto replace a current card operating software with a new card operatingsoftware.
 21. A storage medium tangibly embodying the steps forreplacing a current operating software working with current files in anetwork element comprising a processing element module and a persistentstorage module, each having an active region and a non-active region,said current operating software and said current files residing in saidactive region of said processing element module and said persistentstorage module while said processing element module and said persistentstorage module are active and wherein said non-active region of saidprocessing element module and said non-active region of said persistentstorage module maintain a prior operating software, said stepscomprising: preserving said prior operating software in said non-activeregion of said processing element module and in said non-active regionof said persistent storage module; downloading a new operating softwareto said non-active region of said persistent storage module; installingsaid new operating software in said non-active region of said processingelement module and in said non-active region of said persistent storagemodule; saving said current files; updating said current files to createupdated files conforming with said new operating software; and rebootingwith said network element such that said active region and saidnon-active region of said processing element module are swapped, andsaid active region and said non-active region of said persistent storagemodule are swapped, thereby replacing said current operating softwareworking with said current files with said new operating software workingwith said updated files; wherein said network element concurrentlyutilizes the current operating software and current files residing insaid active region of said processing element module during saiddownloading to said non-active region of said persistent storage moduleand installing of said new operating software in said non-active regionof said processing element module and in said non-active region of saidpersistent storage module; wherein the processing element modulecomprises a first central processing unit, a first physical storage unitfor the active region, and a second physical storage unit for thenon-active region, and the persistent storage module comprises a secondcentral processing unit, a third physical storage unit for the activeregion, and a fourth physical storage unit for the non-active region;and wherein the active region of the processing element module and theactive region of the persistent storage module are synchronized andaccess-locked, and the non-active region of the processing elementmodule and the non-active region of the persistent storage module arenot synchronized and not access-locked.